Negative regulator of NOD2 function. It down-regulates NOD2- induced processes such as activation of NF-kappa-B signaling, IL8 secretion and antibacterial response (PubMed:22700971). Involved in JNK signaling pathway (By similarity). {ECO:0000250|UniProtKB:Q6NS57, ECO:0000269|PubMed:22700971}. This is the function of MAPKBP1 (mitogen-activated protein kinase binding protein 1, Ensembl gene identifier ENSG00000137802).